The present invention relates to improvements in the laundry process, including the provision of methods to improve the odor of fabrics that retain a malodor after the laundry step. The invention also includes odor-absorbing compositions for use in the laundry, especially concentrated additive compositions that can be used selectively on such fabrics and articles comprising said compositions in association with instructions for practicing the method and/or obtaining the benefits that can be derived from the method. Preferably the compositions restore and/or maintain freshness by reducing malodor.
Typical laundry processes remove odors from normal fabrics containing relatively low levels of malodors. However, as the temperature for washing has gotten lower, or when the load has fabrics with high levels of odorants, or when there is some other factor like overloading involved, there is sometimes a lingering malodor. This lingering malodor is different from malodor that is present in some detergent compositions, or is generated after the wash, e.g., by antimicrobial action, or which thereafter becomes attached to the fabrics and is sometimes accompanied by the presence of large amounts of hydrophobic soils. This problem has not been generally recognized, since the general expectation is that the wash cycle removes all odors. However, some consumers have noticed the problem and have taken extreme measures such as doing such fabrics only in separate loads. In general, consumers do not take steps to remove, or counteract the odor, such as, e.g., washing the article again, since the additional measures are not successful. Also, such a second washing is wasteful of time, water, and detergent, and causes increased wear on clothing. Using more detergent is usually undesirable, since that may cause the article to have detergent remaining after the rinse step.
Cyclodextrin has been used to control odors from detergent compositions, to protect perfumes in detergent compositions, improve the solubility of compounds like nonionic surfactants to improve their removal, and like dyes to prevent their transfer to other fabrics by keeping them suspended.
The present invention relates to solving problems associated with having a malodor remaining after the wash process is completed, preferably by the addition of cyclodextrin to help remove/control the malodor, or, less optimally, provide malodor counteractants, like odor blockers or materials that react with the malodors or mask the malodors. The preferred approach uses those materials that result in the removal, or tying up of the malodor. The preferred methods and compositions are used as additives, since the majority of fabric laundry loads do not have the problem and since many of the materials that can neutralize the malodor have their own problems. Cyclodextrin tends to react with perfumes, and surfactants when incorporated in detergent compositions and the level required for malodor control is very high. Odor blockers, when used at the high levels needed for malodor control, block the desirable odors of perfumes as well as the malodors. Similarly, the masking compounds block other desirable odors and reactants can destroy desirable odors.
There is anecdotal information that indicates some consumers may have noticed the problem and have found some ways of solving the problem using materials that are part of the invention herein. However, to avoid causing problems, it is important to provide the general consumer with the identity of the laundry processes, soils, loads, conditions, etc. that typically provide insufficient removal of malodors and the level of ingredients needed to see the benefit. This allows the use of the additive when it is needed. Prior to this invention, the efforts to counteract malodor were based on insufficient information to ensure good results without wasteful use of excess material.
As stated before, in general, provision of such counteractants in the detergent, or fabric softener, is not efficient, since for some loads the benefit is not needed. Also, the level of many ingredients needed to provide good malodor removal/elimination is usually quite high, even for those counteractants that are really effective. Selection of the best counteractant can provide superior results. It is important to avoid the inclusion in the additive compositions of high levels of materials that interfere with the portion of the laundry process where the additive is used. For example, large amounts of acid materials usually hurts detergency by lowering the pH of the wash liquor; anionic materials are usually not compatible with cationic fabric softeners; etc.
The present invention relates to the method of applying an effective amount of a malodor control agent (counteractant) to at least one step of a laundry process to provide a consumer noticeable improvement in the laundry process by either eliminating malodor, or improving the removal of hydrophobic soils, in an efficient way. Generally, because of the high level of ingredients required for this benefit, it is essential to supply the consumer with the requisite information required to make good decisions, e.g., as to when to use the method by defining the areas of greatest benefit, the amount of malodor counteractant required to provide such a benefit, etc. and providing concentrated compositions and delivery methods that minimize the use of too much or too little counteractant. The compositions are preferably supplied in a package in association with this information. The best counteractants provide some residual malodor prevention effects as well as providing superior end results for the laundry process.
The compositions described hereinafter can be used by adding an effective amount to fabrics in one, or more of the steps in a typical laundry cycle including a presoak, a wash step, a rinse step, or a water removal step, e.g., wringing or spinning, drying, etc. An effective amount as defined herein means an amount sufficient to absorb or counteract malodor to the point that it is less objectionable, preferably not discernible by the human sense of smell. As discussed herein, for certain odors, the level in the atmosphere around the fabrics, xe2x80x9chead spacexe2x80x9d, should be less than the minimum detectable concentration for that odor.
The kinds of soils that are most likely to cause a severe malodor include: soils like those found on mechanics"" clothes; food handlers, especially butchers"" and kitchen workers"" clothes; sewer workers"" clothes; bar tenders"" clothes; fire fighters"" clothes; farm clothes; athletic clothing; factory workers"" clothes; heavy machinery operators"" clothes; etc. Such soils have an associated malodor that is almost impossible to counteract without the present invention. Such soils also have a relatively high level of hydrophobic soils such as lubricating oil, grease, food oils, body soils, smoke etc. The preferred cyclodextrin malodor counteractant improves the removal of such soils.
For control of malodors, beta cyclodextrin and alpha cyclodextrin are preferred. Gamma cyclodextrin has too large a cavity to control most malodor molecules. Substituted cyclodextrins can be especially valuable where they are more soluble than the corresponding unsubstituted cyclodextrin. The preferred compositions are concentrated and liquid to minimize packaging while maximizing the speed of action. Cyclodextrins can complex with surfactants and perfumes in the wash or rinse waters, thus it is important to disperse the cyclodextrin as soon as possible. It is surprising that the cyclodextrin is not inactivated by, e.g., the surfactant. Using an additive containing cyclodextrin rather than adding cyclodextrin to the detergent or softening composition minimizes the interaction of the cyclodextrin with the ingredients of the detergent and/or softening compositions.
The level of cyclodextrin required for odor removal is high, but it is much less than that required for solubilizing surfactant. Furthermore, it is important that in any detergent composition or softening composition, the cyclodextrin, if present, should be separated (protected) from the actives that could form complexes with the cyclodextrin if one wants to obtain malodor removal from the laundry fabrics. Cyclodextrin that is added to remove odors from the detergent ingredients or to solubilize surfactants is not available for malodor control. Thus the additive compositions used herein to practice the method are preferably substantially free (i.e., there is not enough of the material so that uncomplexed cyclodextrin is still available.) of materials that will complex with the cyclodextrin, such as enzymes, nonionic surfactants that will complex with the cyclodextrin, maltitol hydroxyl aliphatic ether, cationic softener molecules containing straight alkyl chains, fatty acids and their soaps and derivatives thereof, perfumes that complex with the cyclodextrin, etc.
The level of uncomplexed cyclodextrin is related to the soil and/or odor level. The minimum levels are in progressively preferred approximate amounts, especially as the level of soil/odor increase, about 20 ppm, 30 ppm, 40 ppm, and 60 ppm respectively and the maximum levels in increasing order of preference are about 500 ppm, 300 ppm, 200 ppm, and 110 ppm respectively.
The following table illustrates typical methods of use of a concentrated product of the current invention, as disclosed hereinafter, during a wash or rinse cycle.
The following examples illustrate the surprising added malodor removal benefit of a typical concentrated composition of the current invention to an AATCC (typical generic detergent formula) powder detergent on fabrics during wash or rinse cycle.
As a fabric pretreater, the recommendation is to apply product directly to the soiled fabric evenly. For best results, the instructions are to spray the soiled fabric evenly until slightly damp and then add the garment to the wash.
In the preferred composition, the presence of the surfactant promotes spreading of the solution and the antimicrobial active provides improved odor control as well as antimicrobial action, by minimizing the formation of odors. Both the surfactant and the antimicrobial active provide improved performance and the mixture is especially good.
For compositions containing odor blockers, the level of odor blocker is sufficient to reduce the odor, preferably:from about 0.004 ppm to about 10 ppm, and preferably from about 0.007 to about 5 ppm by weight of the treatment solution, either wash water or rinse water, e.g., the wash or rinse solution in a 20 gallon machine, for normal odor levels and from 0.007 ppm to about 30 ppm and preferably from about 0.01 ppm to about 7 ppm, by weight of the treatment solution for higher odor levels. For materials that react with the odor, like aldehydes, sulfites, etc., the level is preferably: from about 0.05 ppm to about 10 ppm, and preferably from about 0.1 ppm to about 7 ppm, by weight of the treatment solution for normal odor levels and from about 0.1 ppm to about 30 ppm, and preferably from about 0.5 ppm to about 15 ppm, by weight of the treatment solution for higher odor levels. For materials like flavanoids that mask the malodor, the level is preferably: from about 0.1 ppm to about 40 ppm, and preferably from about 0.5 ppm to about 10 ppm, by weight of the treatment solution for normal odor levels and from about 0.2 ppm to about 140 ppm, preferably from about 1 ppm to about 20 ppm by weight of the treatment solution for higher odor levels.
The methods herein are suitable for use with detergent compositions that do not have nonionic detergent surfactants present, or where the level is not sufficient to cause rinsing problems.
The important new information discovered by applicants is that there is a relatively wide spread significant problem associated with high soil loads for some soils as discussed hereinbefore. The problem includes inefficient removal and/or, especially, malodor associated with these soils. Therefore, it is important that any product containing these odor counteractants have sufficient odor counteractant(s) to provide sufficient reduction in soil and/or odor and that the product, preferably in a package, be in association with instructions to use the product at sufficient levels to provide the benefit(s) and that the soils be identified for the consumer.
In addition to the reduction in soil and/or malodor achieved using the present methods that utilize the compositions described herein, the present methods also encompass methods of preventing malodor from developing on fabrics. Malodor prevention is different from malodor reduction or removal, in that malodor prevention is a proactive method to minimize the possibility for malodor to develop on fabrics, especially after being laundered. Malodor typically develops on clothing fabrics either during xe2x80x9cin wearxe2x80x9d conditions of the clothing fabrics or during storage of clothing fabrics, such as in closets or environments susceptible to mold or mildew. The development of malodor on clothing fabrics during xe2x80x9cin wearxe2x80x9d conditions can prove quite embarrassing to the individual wearing the clothing fabrics. The present methods can help prevent these malodors from develop on the clothing fabrics, especially during xe2x80x9cin wearxe2x80x9d conditions.
The present methods of preventing malodor from developing on fabrics comprises the step of adding an effective amount of the compositions described herein to a wash or rinse cycle of a typical laundry process in order to prevent malodor from developing on the fabrics. To obtain malodor prevention, an effective amount of the malodor counteractants described herein needs to be deposited on the fabrics such that a sufficient amount of the malodor counteractant remains on the fabrics after the washing process to prevent malodor from developing on the fabrics.
A preferred malodor counteractant for preventing malodor from developing on fabrics is cyclodextrin. The present methods of preventing malodor from developing on fabrics preferably further comprises depositing an effective amount of cyclodextrin on the fabrics to prevent malodor. Typically, the amount of cyclodextrin to remain on the fabrics to effectively prevent malodor from developing on the fabrics will be at least about 0.001%, preferably at least about 0.01%, and more preferably at least about 0.1%, by weight of the fabric. Furthermore, it is important to provide instructions to a consumer of the compositions of the present invention in order to communicate the malodor prevention benefits of the compositions and instruct the consumer to use the requisite amounts of the compositions to achieve the benefits.
A preferred composition for use in the malodor prevention methods of the present invention comprise cyclodextrin, a cyclodextrin-compatible surfactant, and a cyclodextrin-compatible antimicrobial active. In using this composition, the amount of antimicrobial active remaining on the fabric to provide malodor prevention is typically at least about 0.001%, preferably at least about 0.01%, and more preferably at least about 0.1%, by weight of the fabric.
A typical representative composition that can be used as an additive for use in the laundry process is an odor-absorbing or neutralizing concentrated composition comprising:
(A) optionally, but preferably, an effective amount to absorb malodors, typically from about 0.1% to about 50% by weight of the composition, preferably from about 1% to about 20%, more preferably from about 3% to about 10% by weight of the composition, of solubilized, uncomplexed cyclodextrin;
(B) optionally, an effective amount of odor blocker typically from about 0.0005% to about 1% by weight of the composition, preferably from about 0.001% to about 0.5%, more preferably from about 0.005% to about 0.2% by weight of the composition;
(C) optionally, an effective amount of class I and/or class II aldehydes typically from about 0.01% to about 1% by weight of composition, preferably from about 0.05% to about 0.5%;
(D) optionally, an effective amount of flavanoid, typically from about 0.01% to about 5%, and preferably from about 0.05% to about 1%, by weight of the composition;
(E) optionally, but preferably, an effective amount of water soluble polymer, especially anionic polymer, e.g. polyacrylic acids or their water soluble salts, at a level of from about 0.001% to about 3%, preferably from about 0.005% to about 2%, more preferably from about 0.01% to about 1% by weight of the composition, for improved odor control benefit;
(F) optionally, an effective amount to improve acceptance of the composition, typically from about 0.03% to about 2%, preferably from about 0.1% to about 1%, more preferably from about 0.2% to about 0.5%, by weight of the composition of a solution, emulsion and/or dispersion comprising perfume in addition to said flavanoids and/or odor blocker, preferably containing at least about 50%, more preferably at least about 60%, and even more preferably at least about 70%, and yet still more preferably at least about 80%, by weight of the perfume of perfume ingredients that have a ClogP of greater than about 3, preferably greater than about 3.5 and a molecular weight of greater than 210, preferably greater than about 220, and/or the particle size of said emulsion or dispersion preferably being large enough that it cannot be complexed by said cyclodextrin, when cyclodextrin is present, and where such perfume can, but preferably doesn""t, mask malodor, said perfume, when present, being in addition to the ingredients (B) and/or (C);
(G) optionally, but preferably, an effective amount to improve the performance of the composition, preferably from about 0.01% to about 8%, more preferably from about 0.1% to about 4%, and even more preferably from about 0.5% to about 3%, by weight of the usage composition, of cyclodextrin compatible surfactant that preferably provides a surface tension of from about 20 dyne/cm to about 60 dyne/cm, preferably from about 20 dyne/cm to about 45 dyne/cm;
(H) optionally, at least about 0.01%, preferably at least about 0.05%, and to about 10%, preferably to about 5% by weight, of a soil suspending agent such as a water-soluble substituted or unsubstituted, modified or unmodified polyalkyleneimine soil suspending agent, said soil suspending agent comprising a polyamine backbone;
(I) optionally, an effective amount, to kill, or reduce the growth of microbes, of water soluble antimicrobial active, preferably from about 0.003% to about 2%, more preferably from about 0.01% to about 1.2%, more preferably from about 0.1% to about 0.8%, by weight of the concentrated solution of water soluble antimicrobial active, and said antimicrobial active preferably being selected from the group consisting of halogenated compounds, cyclic nitrogen compounds, quaternary compounds, and phenolic compounds;
(J) optionally, but preferably, from about 0.01% to about 5%, more preferably from about 0.05% to about 2%, and even more preferably from about 0.1% to about 1%, by weight of the usage composition of low molecular weight polyol;
(K) optionally, from about 0.001% to about 1%, preferably from about 0.01% to about 0.3%, more preferably from about 0.02% to about 0.1%, by weight of the usage composition of chelating agent, e.g., aminocarboxylate chelator;
(L) optionally, but preferably, an effective amount of metallic salt, preferably from about 0.1% to about 10%, more preferably from about 0.2% to about 8%, even more preferably from about 0.3% to about 5% by weight of the usage composition, especially water soluble copper and/or zinc salts, for improved odor benefit;
(M) optionally, an effective amount of solubilized, water-soluble, antimicrobial preservative, preferably from about 0.0001% to about 0.5%, more preferably from about 0.0002% to about 0.2%, most preferably from about 0.0003% to about 0.1%, by weight of the composition;
(N) optionally, but preferably, aqueous carrier that optionally can contain up to 20% of a lower molecular weight, water soluble alcohol,
said composition containing at least enough of ingredient (A), (B), (C), (D), and/or (E) to provide significant reduction in malodor that survives a typical laundry wash, and preferably being essentially free of any material that would soil or stain fabric under usage conditions, and/or preferably having a pH of more than about 3, more preferably more than about 3.5, and preferably less than about 13, more preferably less than about 12, and said composition preferably being packaged in association with instructions to use it to counteract malodors, optionally identified, that remain after a typical laundry process, said composition being suitable for use as an additive in pre-treating, washing, and/or rinsing of fabrics and containing only low levels of acidic materials and preferably being essentially free of detergent enzymes and/or nonionic surfactants that interact with cyclodextrin when it is present.
The present invention relates more specifically to a concentrated, stable, preferably clear, aqueous odor-absorbing composition, for use in a laundry process such as a pre-soak, washing step, rinse, or drying step, comprising:
(A) an effective amount to absorb malodors, typically from about 1% to about 20%, preferably from about 3% to about 10% by weight of the composition, of solubilized, uncomplexed cyclodextrin;
(B) optionally, an effective amount of odor blocker typically from about 0.0005% to about 1% by weight of the composition, preferably from about 0.001% to about 0.5%, more preferably from about 0.005% to about 0.2% by weight of the composition;
(C) optionally, an effective amount of class I, class II aldehydes , and mixture of typically from about 0.01% to about 1% by weight of composition, preferably from about 0.05% to about 0.5%.
(D) Optionally, an effective amount of flavanoid, typically from about 0.01% to about 5%, preferably from about 0.05% to about 1%, by weight of the composition;
(E) optionally, but preferably, an effective amount of water soluble anionic polymer, e.g. polyacrylic acids and their water soluble salts, from about 0.001% to about 3%, preferably from about 0.005% to about 2%, more preferably from about 0.01% to about 1% by weight of the composition, for improved odor control benefit;
(F) an effective amount to improve acceptance of the composition, typically from about 0.03% to about 2%, preferably from about 0.1% to about 1%, more preferably from about 0.2% to about 0.5%, by weight of the usage composition of a solution, emulsion and/or dispersion comprising perfume in addition to any ingredient already specified, preferably containing at least about 50%, more preferably at least about 60%, and even more preferably at least about 70%, and yet still more preferably at least about 80%, by weight of the perfume of perfume ingredients that have a ClogP of greater than about 3.0, preferably greater than about 3.5 and a molecular weight of greater than about 210, preferably greater than about 220, and/or the particle size of said emulsion or dispersion preferably being large enough that it cannot be complexed by said cyclodextrin, when cyclodextrin is present, and where such perfume can, but preferably doesn""t, mask malodor, said perfume, when present, being in addition to the ingredients (B) and/or (C);
(G) optionally, an effective amount to improve the performance of the composition, preferably from about 0.01% to about 8%, preferably from about 0.2% to about 4%, more preferably from about 0.3% to about 3%, by weight of the composition, of cyclodextrin compatible surfactant that preferably provides a surface tension of from about 20 dyne/cm to about 60 dyne/cm, preferably from about 20 dyne/cm to about 45 dyne/cm;
(H) optionally, at least about 0.01%, preferably at least about 0.05%, and to about 10%, preferably to about 5% by weight, of a soil suspending agent such as a water-soluble substituted or unsubstituted, modified or unmodified polyalkyleneimine soil suspending agent, said soil suspending agent comprising a polyamine backbone;
(I) optionally, an effective amount, to kill, or reduce the growth of microbes, of water soluble antimicrobial active which is compatible with the other ingredients, preferably from about 0.001% to about 2%, preferably from about 0.01% to about 1.2%, more preferably from about 0.1% to about 0.8%, by weight of the composition, and preferably selected from the group consisting of halogenated compounds, cyclic nitrogen compounds, quaternary compounds, and phenolic compounds;
(J) optionally, but preferably, from about 0.01% to about 6%, more preferably from about 0.05% to about 3%, and even more preferably from about 0.1% to about 2%, by weight of the composition of low molecular weight polyol;
(K) optionally, from about 0.001% to about 1%, preferably from about 0.01% to about 0.5%, more preferably from about 0.02% to about 0.1%, by weight of the usage composition of chelator, e.g., aminocarboxylate chelator;
(L) optionally, but preferably, an effective amount of metallic salt, preferably from about 0.1% to about 10%, more preferably from about 0.2% to about 8%, even more preferably from about 0.3% to about 5% by weight of the composition, especially water soluble copper and/or zinc salts, for improved odor benefit;
(M) optionally, an effective amount of enzyme, from about 0.0001% to about 0.5%, preferably from about 0.001% to about 0.3%, more preferably from about 0.005% to about 0.2% by weight of the composition, for improved odor control benefit;
(N) optionally, an effective amount of solubilized, water-soluble, antimicrobial preservative, preferably from about 0.0001% to about 0.5%, more preferably from about 0.0002% to about 0.2%, most preferably from about 0.0003% to about 0.1%, by weight of the composition;
(O) the balance being aqueous carrier that optionally can contain up to about 20% lower molecular weight water soluble alcohol,
said composition containing at least enough of ingredient (A), (B), (C) and/or (D), to provide significant reduction in malodor that survives a typical laundry wash, and said composition preferably being essentially free of any material that would soil or stain fabric under usage conditions, and/or preferably having a pH of more than about 3, more preferably more than about 3.5, and preferably less than about 13, more preferably less than about 12, and said composition preferably being packaged in association with instructions to use it to counteract malodors that remain after a typical laundry process, said composition being suitable for use as an additive in pretreating, washing, and/or rinsing of fabrics, more preferably with specific instructions, as set forth hereinbefore as to levels of use, and types of odors to treat, and containing only low levels of acidic materials and preferably being essentially free of detergent enzymes.
(A) Cyclodextrin
As used herein, the term xe2x80x9ccyclodextrinxe2x80x9d includes any of the known cyclodextrins such as unsubstituted cyclodextrins containing from six to twelve glucose units, especially, alpha-cyclodextrin, beta-cyclodextrin, gamma-cyclodextrin and/or their derivatives and/or mixtures thereof. The alpha-cyclodextrin consists of six glucose units, the beta-cyclodextrin consists of seven glucose units, and the gamma-cyclodextrin consists of eight glucose units arranged in donut-shaped rings. The specific coupling and conformation of the glucose units give the cyclodextrins a rigid, conical molecular structures with hollow interiors of specific volumes. The xe2x80x9cliningxe2x80x9d of each internal cavity is formed by hydrogen atoms and glycosidic bridging oxygen atoms; therefore, this surface is fairly hydrophobic. The unique shape and physical-chemical properties of the cavity enable the cyclodextrin molecules to absorb (form inclusion complexes with) organic molecules or parts of organic molecules which can fit into the cavity. Many odorous molecules can fit into the cavity including many malodorous molecules and perfume molecules. Therefore, cyclodextrins, and especially mixtures of cyclodextrins with different size cavities, can be used to control odors caused by a broad spectrum of organic odoriferous materials, which may, or may not, contain reactive functional groups. The complexation between cyclodextrin and odorous molecules occurs rapidly in the presence of water. However, the extent of the complex formation also depends on the polarity of the absorbed molecules. In an aqueous solution, strongly hydrophilic molecules (those which are highly water-soluble) are only partially absorbed, if at all. Therefore, cyclodextrin does not complex effectively with some very low molecular weight organic amines and acids when they are present at low levels on wet fabrics. As the water is being removed however, e.g., the fabric is being dried off, some low molecular weight organic amines and acids have more affinity and will complex with the cyclodextrins more readily.
The cavities within the cyclodextrin in the solution of the present invention should remain essentially unfilled (the cyclodextrin remains uncomplexed) while in solution, in order to allow the cyclodextrin to absorb various odor molecules when the solution is applied to a surface. Non-derivatised (normal) beta-cyclodextrin can be present at a level up to its solubility limit of about 1.85% (about 1.85 g in 100 grams of water) under the conditions of use at room temperature.
Preferably, the odor absorbing solution of the present invention is clear. The term xe2x80x9cclearxe2x80x9d as defined herein means transparent or translucent, preferably transparent, as in xe2x80x9cwater clear,xe2x80x9d when observed through a layer having a thickness of less than about 10 cm. However, one can suspend undissolved cyclodextrin such as beta-cyclodextrin, uniformly in a higher viscosity liquid or gel
Preferably, the cyclodextrins used in the present invention are highly water-soluble such as, alpha-cyclodextrin and/or derivatives thereof, gamma-cyclodextrin and/or derivatives thereof, derivatised beta-cyclodextrins, and/or mixtures thereof. The derivatives of cyclodextrin consist mainly of molecules wherein some of the OH groups are converted to OR groups. Cyclodextrin derivatives include, e.g., those with short chain alkyl groups such as methylated cyclodextrins, and ethylated cyclodextrins, wherein R is a methyl or an ethyl group; those with hydroxyalkyl substituted groups, such as hydroxypropyl cyclodextrins and/or hydroxyethyl cyclodextrins, wherein R is a xe2x80x94CH2xe2x80x94CH(OH)xe2x80x94CH3 or a xe2x88x92CH2CH2xe2x80x94OH group; branched cyclodextrins such as maltose-bonded cyclodextrins; cationic cyclodextrins such as those containing 2-hydroxy-3-(dimethylamino)propyl ether, wherein R is CH2xe2x80x94CH(OH)xe2x80x94CH2xe2x80x94N(CH3)2 which is cationic at low pH; quaternary ammonium, e.g., 2-hydroxy-3-(trimethylammonio)propyl ether chloride groups, wherein R is CH2xe2x80x94CH(OH)xe2x80x94CH2xe2x80x94N+(CH3)3Clxe2x88x92; anionic cyclodextrins such as carboxymethyl cyclodextrins, cyclodextrin sulfates, and cyclodextrin succinylates; amphoteric cyclodextrins such as carboxymethyl/quaternary ammonium cyclodextrins; cyclodextrins wherein at least one glucopyranose unit has a 3-6-anhydro-cyclomalto structure, e.g., the mono-3-6-anhydrocyclodextrins, as disclosed in xe2x80x9cOptimal Performances with Minimal Chemical Modification of Cyclodextrinsxe2x80x9d, F. Diedaini-Pilard and B. Perly, The 7th International Cyclodextrin Symposium Abstracts, April 1994, p. 49, said references being incorporated herein by reference; and mixtures thereof. Other cyclodextrin derivatives are disclosed in U.S. Pat. No.: 3,426,011, Parmerter et al., issued Feb. 4, 1969; U.S. Pat. Nos. 3,453,257; 3,453,258; 3,453,259; and 3,453,260, all in the names of Parmerter et al., and all issued Jul. 1, 1969; U.S. Pat. No. 3,459,731, Gramera et al., issued Aug. 5, 1969; U.S. Pat. No. 3,553,191, Parmerter et al., issued Jan. 5, 1971; U.S. Pat. No. 3,565,887, Parmerter et al., issued Feb. 23, 1971; U.S. Pat. No. 4,535,152, Szejtli et al., issued Aug. 13, 1985; U.S. Pat. No. 4,616,008, Hirai et al., issued Oct. 7, 1986; U.S. Pat. No. 4,678,598, Ogino et al., issued Jul. 7, 1987; U.S. Pat. No. 4,638,058, Brandt et al., issued Jan. 20, 1987; and U.S. Pat. No. 4,746,734, Tsuchiyama et al., issued May 24, 1988; all of said patents being incorporated herein by reference. Further cyclodextrin derivatives suitable herein include those disclosed in V. T. D""Souza and K. B. Lipkowitz, Chemical Reviews: Cyclodextrins, Vol. 98, No. 5 (American Chemical Society, July/August 1998), which is incorporated herein by reference.
Highly water-soluble cyclodextrins are those having water solubility of at least about 10 g in 100 ml of water at room temperature, preferably at least about 20 g in 100 ml of water, more preferably at least about 25 g in 100 ml of water at room temperature. The availability of solubilized, uncomplexed cyclodextrins is essential for effective and efficient odor control performance. Solubilized, water-soluble cyclodextrin can exhibit more efficient odor control performance than non-water-soluble cyclodextrin when deposited onto surfaces, especially fabric.
Examples of preferred water-soluble cyclodextrin derivatives suitable for use herein are hydroxypropyl alpha-cyclodextrin, methylated alpha-cyclodextrin, methylated beta-cyclodextrin, hydroxyethyl beta-cyclodextrin, and hydroxypropyl beta-cyclodextrin. Hydroxyalkyl cyclodextrin derivatives preferably have a degree of substitution of from about 1 to about 14, more preferably from about 1.5 to about 7, wherein the total number of OR groups per cyclodextrin is defined as the degree of substitution. Methylated cyclodextrin derivatives typically have a degree of substitution of from about 1 to about 18, preferably from about 3 to about 16. A known methylated beta-cyclodextrin is heptakis-2,6-di-O-methyl-xcex2-cyclodextrin, commonly known as DIMEB, in which each glucose unit has about 2 methyl groups with a degree of substitution of about 14. A preferred, more commercially available, methylated beta-cyclodextrin is a randomly methylated beta-cyclodextrin, commonly known as RAMEB, having different degrees of substitution, normally of about 12.6. RAMEB is more preferred than DIMEB, since DIMEB affects the surface activity of the preferred surfactants more than RAMEB. The preferred cyclodextrins are available, e.g., from Cerestar USA, Inc. and Wacker Chemicals (USA), Inc.
It is also preferable to use a mixture of cyclodextrins. Such mixtures absorb odors more broadly by complexing with a wider range of odoriferous molecules having a wider range of molecular sizes. Preferably at least a portion of the cyclodextrins is alpha-cyclodextrin and its derivatives thereof, gamma-cyclodextrin and its derivatives thereof, and/or derivatised beta-cyclodextrin, more preferably a mixture of alpha-cyclodextrin, or an alpha-cyclodextrin derivative, and derivatised beta-cyclodextrin, even more preferably a mixture of derivatised alpha-cyclodextrin and derivatised beta-cyclodextrin, most preferably a mixture of hydroxypropyl alpha-cyclodextrin and hydroxypropyl beta-cyclodextrin, and/or a mixture of methylated alpha-cyclodextrin and methylated beta-cyclodextrin.
Uncomplexed cyclodextrin molecules, which are made up of varying numbers of glucose units provide the absorbing advantages of known absorbent deodorizing compositions without harmful effects to fabrics. While cyclodextrin is an effective odor absorbing active, some small molecules are not sufficiently absorbed by the cyclodextrin molecules because the cavity of the cyclodextrin molecule may be too large to adequately hold the smaller organic molecule. If a small sized organic odor molecule is not sufficiently absorbed into the cyclodextrin cavity, a substantial amount of malodor can remain. In order to alleviate this problem, low molecular weight polyols can be added to the composition as discussed hereinafter, to enhance the formation of cyclodextrin inclusion complexes. Furthermore, optional water soluble metal salts can be added as discussed hereinafter, to complex with some nitrogen-containing and sulfur-containing malodor molecules.
Since cyclodextrin is a prime breeding ground for certain microorganisms, especially when in aqueous compositions, it is preferable to include a water-soluble antimicrobial preservative, which is effective for inhibiting and/or regulating microbial growth, to increase storage stability of aqueous odor-absorbing solutions containing water-soluble cyclodextrin, when the composition does not contain an antimicrobial material as described hereinafter.
It is also desirable to provide optional ingredients such as a cyclodextrin compatible antimicrobial active that provides substantial kill of organisms that cause, e.g., odor, infections, etc. It is also desirable that the compositions contain a cyclodextrin compatible surfactant to promote spreading of the odor absorbing composition on hydrophobic surfaces such as polyester, nylon, etc. as well as to penetrate any oily, hydrophobic soil for improved malodor control. Furthermore, it is desirable that the cyclodextrin-compatible surfactant provide in-wear electrostatic control. It is more preferable that the odor absorbing composition of the present invention contain both a cyclodextrin-compatible antibacterial active and a cyclodextrin-compatible surfactant. A cyclodextrin-compatible active is one which does not substantially form a complex with cyclodextrin in the composition, at the usage concentration, so that an effective amount of both the free, uncomplexed active and free, uncomplexed cyclodextrin are available for their intended uses. Furthermore, it is desirable to include a humectant to maintain a desirable moisture level in cotton fabrics while they dry to maximize dewrinkling.
For controlling odor on fabrics, the composition is preferably used as an additive to the washing step of a laundry process to maximize the odor removal and to take advantage of the cleaning benefit that can be achieved by the use of high levels of cyclodextrin. Specifically, soils that contain high levels of hydrophobic, oily soils, can be removed more completely by the addition of cyclodextrin. This more complete removal is partly due to solubilization from the fabric and partly due to the suspension of the soil. Cyclodextrin also provides softening and anti-wrinkling benefits when used at these high levels. Surprisingly, the interaction of the cyclodextrin and surfactants is minimal when the cyclodextrin is added as part of an additive due to the lack of time and/or concentration required to form complexes.
While a more dilute composition can be used, concentrated compositions are preferably used in order to deliver a less expensive and/or less bulky product, i.e., when the level of cyclodextrin used is from about 2% to about 60%, more preferably from about 3% to about 30%, by weight of the concentrated composition.
(B) Odor Blockers
Although not preferred, odor blockers can be used to mitigate the effects of malodors. In order to be effective, the blockers normally have to be present at all times. If the odor blocker evaporates before the source of the odor is gone, it is less likely to control the odor. Also, the odor blockers tend to adversely affect aesthetics by blocking the wanted odors like perfumes.
Suitable odor xe2x80x9cblockersxe2x80x9d are disclosed in U.S. Pat. Nos. 4,009,253; 4,187,251, 4,719,105; 5,441,727; and 5,861,371, said patents being incorporated herein by reference.
(C) Aldehydes
As an optional ingredient, aldehydes can be used to mitigate the effects of malodors. Suitable aldehydes are class I, class II aldehydes, and mixture of such aldehydes that are disclosed in U.S. Pat. No. 5,676,163, said patent being incorporated herein by reference.
(D) Flavanoids
Flavanoids are ingredients found in typical essential oils. Such oils include essential oil extracted by dry distillation from needle leaf trees and grasses such as cedar, Japanese cypress, eucalyptus, Japanese red pine, dandelion, low striped bamboo and cranesbill and it contains terpenic material such as alpha-pinene, beta-pinene, myrcene, phencone and camphene. The terpene type substance is homogeneously dispersed in the finishing agent by the action of nonionic surfactant and is attached to fibres constituting the cloth. Also included are extracts from tea leaf. Descriptions of such materials can be found in JP6219157, JP 02284997, JP04030855, etc. said references being incorporated herein by reference.
(E) Perfume
The odor absorbing composition of the present invention can also provide a xe2x80x9cscent signalxe2x80x9d in the form of a pleasant odor which signals the removal of malodor from fabrics. The perfume herein is in addition to perfume ingredients that fulfill the role of odor counteractant, and are designed to provide, at least in part, a lasting perfume scent. Perfume is added at levels of from about 0% to about 1%, preferably from about 0.003% to about 0.3%, more preferably from about 0.005% to about 0.2%, by weight of the usage composition.
Perfume is added to provide a more lasting odor on surfaces. When stronger levels of perfume are preferred, relatively higher levels of perfume can be added. Any type of perfume can be incorporated into the composition of the present invention so long as the preferred hydrophobic perfume that will complex with the cyclodextrin is formed into an emulsion with a droplet size that will not readily interact with the cyclodextrin in the composition. The perfume ingredients can be either hydrophilic or hydrophobic.
If the perfume ingredients are hydrophilic, they should be dissolved in the aqueous phase so they do not complex with the cyclodextrin when it is present. It is important to note that for best product stability and improved cyclodextrin compatibility, a clear premix consisting of hydrophilic perfume ingredients, cyclodextrin compatible surfactant, and solubility aid (for example, ethanol) is firstly made so that all hydrophilic perfume ingredients are pre-dissolved. Cyclodextrin, water hold and optional ingredients are always added during the final mixing stage. In order to reserve an effective amount of cyclodextrin molecules for odor control, hydrophilic perfume ingredients are typically present at a level wherein less than about 90% of the cyclodextrin complexes with the perfume, preferably less than about 50% of the cyclodextrin complexes with the perfume, more preferably, less than about 30% of the cyclodextrin complexes with the perfume, and most preferably, less than about 10% of the cyclodextrin complexes with the perfume. The cyclodextrin to perfume weight ratio should be greater than about 8:1, preferably greater than about 10:1, more preferably greater than about 20:1, even more preferably greater than 40:1 and most preferably greater than about 70:1.
Hydrophilic perfumes are composed predominantly of ingredients having a ClogP of less than about 3.5, more preferably less than about 3 and, preferably, lower molecular weights, e.g., below about 220, preferably below about 210. If longer lasting perfume effects are desired, the hydrophobic perfumes disclosed below are used.
(a) Hydrophobic Perfume Ingredients
In order to provide long lasting effects, the perfume is at least partially hydrophobic and has a relatively high boiling point. I.e., it is composed predominantly of ingredients selected from two groups of ingredients, namely, (a) hydrophilic ingredients having a ClogP of more than about 3, more preferably more than about 3.5, and (b) ingredients having a molecular weight above about 210, preferably above about 220. Typically, at least about 50%, preferably at least about 60%, more preferably at least about 70%, and most preferably at least about 80% by weight of the perfume is composed of perfume ingredients of the above groups (a) and (b). For these preferred perfumes, the cyclodextrin to perfume weight ratio is typically of from about 2:1 to about 200:1; preferably from about 4:1 to about 100:1, more preferably from about 6:1 to about 50:1, and even more preferably from about 8:1 to about 30:1.
Hydrophobic perfume ingredients have a tendency to complex with the cyclodextrins. The degree of hydrophobicity of a perfume ingredient can be correlated with its octanol/water partition coefficient P. The octanol/water partition coefficient of a perfume ingredient is the ratio between its equilibrium concentration in octanol and in water. A perfume ingredient with a greater partition coefficient P is considered to be more hydrophobic. Conversely, a perfume ingredient with a smaller partition coefficient P is considered to be more hydrophilic. Since the partition coefficients of the perfume ingredients normally have high values, they are more conveniently given in the form of their logarithm to the base 10, logP. Thus the preferred perfume hydrophobic perfume ingredients of this invention have a logP of about 3 or higher, preferably of about 3.5 or higher.
The logP of many perfume ingredients have been reported; for example, the Pomona92 database, available from Daylight Chemical Information Systems, Inc. (Daylight CIS), Irvine, Calif., contains many, along with citations to the original literature. However, the logP values are most conveniently calculated by the xe2x80x9cCLOGPxe2x80x9d program, also available from Daylight CIS. This program also lists experimental logP values when they are available in the Pomona92 database. The xe2x80x9ccalculated logPxe2x80x9d (ClogP) is determined by the fragment approach of Hansch and Leo (cf., A. Leo, in Comprehensive Medicinal Chemistry, Vol. 4, C. Hansch, P. G. Sammens, J. B. Taylor and C. A. Ramsden, Eds., p. 295, Pergamon Press, 1990, incorporated herein by reference). The fragment approach is based on the chemical structure of each perfume ingredient, and takes into account the numbers and types of atoms, the atom connectivity, and chemical bonding. The ClogP values, which are the most reliable and widely used estimates for this physicochemical property, are used instead of the experimental logP values in the selection of perfume ingredients which are useful in the present invention.
Non-limiting examples of the more preferred hydrophobic (enduring) perfume ingredients are selected from the group consisting of: diethyl phthalate, methyl dihydro jasmonate, lyral, hexyl salicylate, iso-E super, hexyl cinnamic aldehyde, iso-propyl myristate, galaxolide, phenyl-ethyl-phenyl acetate, cis-jasmone; dimethyl benzyl carbinyl acetate; ethyl vanillin; geranyl acetate; alpha-ionone; beta-ionone; gamma-ionone; lauric aldehyde; methyl dihydrojasmonate; methyl nonyl acetaldehyde; gamma-nonalactone; phenoxy ethyl iso-butyrate; phenyl ethyl dimethyl carbinol; phenyl ethyl dimethyl carbinyl acetate; alpha-methyl-4-(2-methylpropyl)-benzenepropanal (Suzaral T); 6-acetyl-1,1,3,4,4,6-hexamethyl tetrahydronaphthalene (Tonalid); undecylenic aldehyde; vanillin; 2,5,5-trimethyl-2-pentyl-cyclopentanone (veloutone); 2-tert-butylcyclohexanol (verdol); verdox; para-tert-butylcyclohexyl acetate (vertenex); and mixtures thereof. Enduring perfume compositions can be formulated using these enduring perfume ingredients, preferably at a level of at least about 5%, more preferably at least about 10%, and even more preferably at least about 20%, by weight of the enduring perfume composition, the total level of enduring perfume ingredients, as disclosed herein, being at least about 70%, all by weight of said enduring perfume composition.
Other enduring perfume ingredients that can be used with the above named enduring perfume ingredients can be characterized by boiling point (B.P.) and octanol/water partitioning coefficient (P). The octanol/water partitioning coefficient of a perfume ingredient is the ratio between its equilibrium concentrations in octanol and in water. These other enduring perfume ingredients of this invention have a molecular weight of more than about 210, preferably more than about 220; and an octanol/water partitioning coefficient P of about 1,000 or higher. Since the partitioning coefficients of these other enduring perfume ingredients of this invention have high values, they are more conveniently given in the form of their logarithm to the base 10, logP. Thus these other enduring perfume ingredients of this invention have logP of about 3 or higher, preferably more than about 3.1, and even more preferably more than about 3.2.
The following table illustrates the molecular weight property of some of the preferred perfume versus non-preferred perfume components.